Portable gantry crane



May 17, 1960 R. n. WOODRUFF PORTABLE GANTRY CRANE 3 Sheets-Sheet 1 K0 I 7 w Filed NOV. 1, 1957 INVENTOR. RALPH D. WOODRUFF WM ATTORNEY FIG. 2

y 1960 R. D. WOODRUFF 2,936,907

PORTABLE GANTRY CRANE 5 Sheets-Sheet 2 Filed NOV. 1, 1957 31 ,ao' y I INVENTOR.

RQLPH D. WOODRUF F BY f A HTTORNZEY i May 17, 1960 Filed Nov. 1, 1957 R. D. WOODRUFF 2,936,907

PORTABLE GANTRY CRANE 3 Sheets-Sheet 3 61 66 57 r 59 g 1OI\/ 100 5 0 m2 INVENTOR.

RALPH n. WOODRUFF HTTORNEY D. W. Winkelman Company, Onondaga County, N.Y., a corporation of New York Application November 1, 1957 Serial No. 693311 5 Claims. (Cl. 212*13) This invention relates to gantry cranes, and more particularly, to a portable gantry crane adaptedfor heavy duty use. This invention provides for a portable apparatus adapted to lift and move loads toan infinite number of points within a given area of operation.

In the past, various embodiments of gantry type cranes have been presented. However, these types have been adapted to one or more specific uses, but were generally limited in their overall adaptability to diversified types of work. One such type of gantry crane is the type seen in factories. This crane comprises an overhead crane beam having wheel trucks at either end, and adapted to be propelled over stationary rails at either side of the area of operation. A powered trolley and a winch for hoisting are disposed on rails on the crane beam. The whole is most commonly powered by electricity from the factory supply. This type'of crane is a single-purpose type, and is not adapted to be dismantled and moved to United em n g another location. The crane beam is inherently heavy and massive, and the power source is both expensive,

and non-reusable. I

Another type is the folding mobile type .of, crane,

wherein the crane beam forms the chassis of a mobile trailer having wheels and adapted to be pulled behind a tractor or the like. The trailer is towed to the area of operation and unhitched from the tow vehicle. ..f1he up right end sections are then unfolded from their bed in the trailer into an upright condition, and the crane beam is elevated to the desired height for operation. The major disadvantage of this type crane is that, once set up, it is stationary on the ground, and is useful only to the extent that a loaded carrier is moved under the crane beam and unloaded. Another carrier is then moved under the beam and the load is thence transferred to'the second carrier. 7

Another type of gantry crane includes a substantially unitary rigid framework comprising an overhead crane beam supported by an upright section at either end, and

adapted to be propelled over tracks fixedly vlaid in the area of operations. disposed on the crane beam for transfer of loads and the like. The crane is somewhat flexible in its operation in that several types of work may be performed. However, should it be required to extend the range of operation of this crane, substantially permanent installation of more track is required in order that the crane may be made to perform eifectively and efiiciently.

Accordingly, it is a leading object of the present invention to provide a portable gantry crane for heavy duty operation which is adapted to be dismantled into sections and re-assembled on location as required.

Another leading object of this invention is to provide a gantry crane which is completely self-contained and self-powered and fully synchronized in its operation.

It is a further object of this invention to provide a portable gantry crane which is adapted to move on tracks in the area of operation, and which is further adapted to lay and pick up its own track as required.

Another object of this invention is to provide a port- A trolley with a hoisting winch is 2,936,907 Patented May 17, 1960 'ice 2 able gantry crane. adapted to be assembled in different widths, as the job requires.

A further object of this invention is to provide a "gantry crane which is completely, internally powered from a single power source. a

In accordance with the above objects, a portable gantry crane is provided having four basic elements. These are the crane beam, the two end frames, and the power source and operating unit. The crane is assembled, with the crane beam assembled in the length required to adaptthe crane to the job at any time when the job may call for a crane of specific width. The crane is well adapted for use in transferring loads from one carrier to another; transfer of a load from a carrier to an infinite point within the area of operation; and transfer of a load from an infinite point within the area of operation out of said area to a carrier. It is seen in the secondly-mentioned use, that under certain conditions, it is either i m-- possible, or undesirable that a carrier be moved onto a location within the area of operation of the crane. The crane may thus span this location,- and transfer the load from the carrier into the location, or conversely;

The use of an apparatus of this type in the foregoing situation thus serves to eliminate a large amount of expensive man-hours and manual labor, in addition to shortening the amount of time to be consumed in performing the work.

The accomplishment of the above and other objects will be better understood by the description in the following specification, when taken with reference to the portable crane, with some details omitted, and further pointing out some of the salient features thereof.

Figure 6 is an enlarged view of a flexible hydraulic connection.

Figure 7 is a fragmentary perspective view of an end portion of a modified crane beam of the novel gantry crane.

In the drawings, and in the following specification, an embodiment of theportable gantry crane is disclosed which is particularly useful for placing a large bucket or hopper of concrete at any point on a bridge under construction. It will also become obvious that, as soon as the main longitudinal stringers of the'bridge are in place, the crane may be set up for placing other materials in position for installation of reinforcing bridge members, and other falsework and forms which carry the deck concrete. This embodiment is for the purpose of illustration only, and not for the purpose of limitation.

With reference to Figure 1, there is illustrated a crane having basically a pair of end frames supporting a main, overhead crane beam 50. Each end frame is made up of a pair of upright members or elements 20 carried on a wheel truck structure 30, and connected together at the.

means of lateral reinforcing steel plates 22 welded in place. The top beam 21 comprises a pair of channel members placed face to face. Conventional brackets are then welded at substantially the ends of the top beam,

and the brackets carrying the beam are then bolted to the upright members 20. The wheel trucks 30, which form the lower or bottom member of the end frames 20, are similarly constructed of a pair of channel members placed face to face. This construction is best illustrated in Figures 3 and 5.

The crane beam 50 comprises a primary longitudinal member 51 which is formed from a conventional I-bea'm. Tubular longitudinal members 52 are formed through the length of the member 51, and parallel therewith. Cross braces 54 are welded in place, and additional diagonal braces 53are also welded in place." This is all designed according to engineering practices which determine the size and placement of members 51, 52, 53, and 54 according to the requirements as to load capacity. Extra heavy steel pipe is preferably used for the tubular elements, the size and spacing of which is determined according to the load requirements. This construction is obvious from Figures 3 and 5. A mounting brackets 55 are welded to the top longitudinal members 52. Holes are drilled through the substantially horizontal portion of these brackets 55; and holes are also drilled through the lower flange-like portion of the top beams 21. Bolts 56 are then placed through the holes in the top beams 21, and through aligning holes in the bracket 55 for mounting the crane beam in place, suspended under the top beam 21 of the end frames.

With reference to Figures 1 and 3, it will be seen that the bottom member or wheel truck member 30 of one end frame is longer than that of the other end frame. This extended portion 36 of one of the members 30 is formed to carry the power unit for the crane, to be further described. Figure 3 illustrates an elevation of one of the end frames, having the extended portion 36 supporting the power unit. The other end frame is identical with the one illustrated with the exception that the other end frame is terminated in its bottom member 30' at point 37, indicated by an arrow and a broken line.

The whole structure is maintained substantially rigidly by means of end braces 67. A pair of these braces 67 disposed at each end of the crane, between the end frame and the longitudinal members 52 of the top crane beam 50. Each brace comprises an upper end 61 adapted to be telescoped into or out of a central section 62 and held in place by suitable bolts or pins 63. In this manner, the length of the braces 67 may be varied slightly to compensate for conditions of the disposition of the crane as a whole. The upper ends 61 of braces 67 are pivotally mounted on brackets 66 welded to the members 52, and the lower ends 65 of the braces 67 are likewise mounted pivotally to a bracket 66 welded to the end frames. Between the lower end 65 and the central section 62 of the braces 67 there is placed a conventional turnbuckle 64 for making fine adjustments as to the length of the braces 67. It will become obvious that, for efficient and eifective operation of the crane, the angle between the end frames and the crane beam must be as close as possible to a precise 90. When the crane is set up, the upper end 61 and the central section 62 are adjusted to the approximate correct length to provide the angle of 90, and the bolts 63 are then placed in aligning holes through the members 61 and 62. The turnbuckles 64 are then adjusted to make the fine adjustment for the 90 angle.

The crane is adapted to roll on tracks by means of the flanged wheels 31. A pair of axles 33 are disposed transversely through the wheel trucks 30 on suitable bearings 35. Wheels 31 are mounted on the axles 33 in a conventional manner so that the Wheels and axles turn as a unit, and a wheel may not turn unless its axle also turns. An extended portion of axle 33 is adapted to have placed thereon, a sprocket 34 for a roller chain, which will be further described.

Figures 3 and illustrate a portion of a main bridge girder 46, being a longitudinal member substantially at the side of the bridge and running the distance from end to end of the bridge, there being one at each side thereof. A track of conventional type is adapted to be placed over the girder 46, and supported thereby by means of special track supports 41, Figures 3 and 4. These supports 41 are made up of four upright elements or legs 43 of steel pipe or the like, held together by cross braces 44 welded to the legs. A steel plate is welded across the top, and has a pair of holes drilled therethrough to receive bolts and clamps 42 held thereby. These bolts and clamps 42, are of any conventional type adapted to hold the track 40 and the track support 41 together. Reinforcing bars 45 are welded as at 49 to the underside of each length of track in order to further reinforce the rail 40 against the weight of the crane. Sections of track are joined together end-to-end in any conventional manner.

There is conventionally placed on the girder 46, a spiral 47. This spiral 47 is a spring steel coil used to absorb expansion and contraction of bridge members during temperature change thereof. The legs 43 of the track supports 41 are placed on the girder 46 so as to straddle the spiral 47, and wooden wedges 48 are placed under the spiral 47 and against the legs 43 of the support 41 to maintain the support in its position. The track 40 being fastened to the supports 41 is thus maintained in position over the girder 46 of the bridge, and supported thereby. It is to be understood that a plurality of track supports 41 are used, in spaced position, to support the track 40.

In this manner, the track supports the weight of the crane above and away from all falsework and other forms and structure which carry the deck concrete of the bridge. Thus no strain of any kind is placed on these forms (not shown), during the pouring of the deck concrete.

The width of the crane is adapted to be varied by varying the length of the crane beam 50. This is done by means of joints 57 in the crane beam 50. The beam is made up in sections, as illustrated in Figure 5, and is also shown in Figure 1. At each end of a section, the tubular members 52 are provided with flanges 58 having bolt holes through the face thereof. When two sections are joined together, the faces of the flanges 58 are mated, and bolts are placed therethrough and fastened. Connecting plates 59 are placed at the top, bottom, and sides of the primary beam 51, and bolted thereat. Thus, the crane beam 50 is adapted to be assembled in widths to fit any size bridge. Further adjustment may be made by means of a plurality of holes (not shown) in the mounting bracket 55. According to the width crane required, the associated holes are lined up with the holes in the top beam 21 of the end frame, and the crane beam is then bolted thereat to the top beam 21. The end braces 67 are adjusted accordingly.

Each end frame has mounted thereon, a swing arm or yardarm 25 '(only one being shown). This yardarm is pivotally mounted on a rollpin or bolt 24 through any suitable pivot bearing structure 23. At the outer end of the arm 25 is a cable sheave 26 over which a cable 28 is adapted to travel. At the extreme end of the cable is a hook 27 or other arrangement such as a sling, to facilitate the lifting of articles. A hydraulic cylinder 83 is mounted longitudinally in the arm 25, and the end of the cable 28 is fastened in any conventional manner to the end of the piston rod 93 of the cylinder 83. The arm 25 may be formed from channel stock, or I-beam stock, as required by load capacity, and the cylinder 83 thus mounted in the channel formed by the construction of. the arm. The cylinder 83 is a single acting type. As fluid pressure is supplied through line 81, the piston (not shown) is forced to the other end, thus retracting piston rod 93, and pulling the cable 28 over the sheave 26, lifting the hook 27. When pressure in line 81 is released, the piston is allowed to return to normal position, forcing the piston rod 93 out of the cylinder 83, and lower- 'ing the hook 27. The am, being pivotally mounted, is

These trolleys 100 are of conventional type. Any suit-' able load bar 102 connects the trolleys together. A double acting hydraulic cylinder 87 is pivotally suspended from the load bar 102 by means of connector 104. Piston rod 97 of cylinder 87 is adapted to be forced out of the cylinder or retracted by means of fluid pressure supplied through hydraulic lines 81. A connector 98 on the end of the rod 97 adapts the rod 97 to have the bucket or hopper 99. fastened thereto for hoisting and lowering of the bucket 99. At one end of the crane beam, Figure 1, a reversible hydraulic motor 86 of conventional type is mounted, and receives fluid pressure for actuation thereof. The motor 86 is adapted to drive a conventional idler sprocket 105 having a roller chain of conventional type 103 disposed thereon. The chain 103 is fastened at either end to the load bar 102, then over the idler sprocket 105 at the other end of crane beam 50, along the crane beam, and over any conventional type idler sprocket 109, Figure (more than one being provided), and over the driven sprocket 105, thence back to the load bar 102. In this manner, the trolleys 100 are adapted to be driven or propelled along the length of the main beam 51, in either direction.

Disposed on each wheel truck 30, is a reversible hydraulic motor 85, and an associated drive mechanism 95, all of conventional type. The motor 85 is actuated by fluid pressure to turn the drivemechanisrn 95. Each wheel 31 has an associated sprocket for a roller chain disposed on its axle. This sprocket 34 is connected to the drive mechanism 95 by means of a conventional roller chain. Thus, the entire crane is adapted to be propelled in either direction along the tracks 40, Figure 1. Any suitable hood or shield 29 is formed around the motor 85 and drive mechanism 95 to protect against POS'.

sible damage. The motors 85 are synchronized for simultaneous actuation, as will be further described.

Brakes are provided to hold the crane against movement along the tracks 40, or to halt movement along the tracks. The brakes, Figure 5, comprise a brake shoe 106 of conventional type disposed on the end of the piston rod 108 of hydraulic cylinder 88, a conventional single-acting cylinder, which is actuated by fluid pressure in line 81. The brakes are held normally on by means of a loading spring 107 placed around the piston rod 108 and between the brake shoe 106 and the bracket which holds the cylinder 88. A brake of this type of construction is provided at each wheel, and the brakes are mounted in the upright members 20 of the end frames. When it is desired to release the brakes, a valve is opened, supplying fluid pressure to the cylinders 88, thus retracting the piston rods 107 against the urging of the spring 108, and releasing the brake shoes from constant engagement against the wheels 31.

Figure 1 illustrates an embodiment of a suitable power unit for the crane. An engine 89.is adapted to drive a hydraulic pump or pumps 71 by means of drive belts 90 and associated pulleys. The pumps 71- force hydraulic fluid underpressure from reservoir 70 to the hydraulic lines 81 through operating valves 80. The lines 81 are all of conventional type. Flexible lines 81A, Figure 6, connect the valves 80 to rigid lines 81 disposed in the upright members 20 of the end frames (not shown). Rigid lines 81 are suspended from the cross braces 54 of the crane beam, Figure 3; and flexible connectors 81A, Figure 6, are used at the joints 57 in the crane beam sections between the rigid lines 81, between the end frames and the crane beam, and between the power unit. and the end frame. The use. of. detachable flexible hydraulic connecting lines is all conventional} will not be described further. Any suitable support 60, Figure l, is used to support lines 81 for bucket cylinder 87. As this cylinder is'adapted to be propelled the length of crane beam 50, sufficient hose 81 is suspended from support 60 to reach cylinder 87 at either end of the crane beam.

Figure 2 is a schematic of the hydraulic system ac cording to the present embodiment. A reservoir 70 of fluid is connected by pumps 71 to associated valves. The reference numerals on the cylinders and motors correspond to those on the several views of the in-' vention. One pump 71 is connected to the valve block 80 to supply fluid pressure to all of the valves 80 thereat. Gauge G indicates the pressure in the lines at all times. Valve 76 supplies fluid pressure through lines 81 to motor 86 (trolley motor) when it is required to propel the trolleys 100 in either direction. Valve supplies fluid pressure to the wheel motors 85. These motors 85 are connected in parallel, in order to maintain uniform pressure in each of the wheel motors so that even starting and uniform speed of rotation of all four wheels is maintained. A choke CK is inserted in one of the lines 81 to guard against surge pressure when starting the wheel motors 85. This serves to avoid against jerking movement when propelling the crane on the tracks 40, thus guarding against possible damage to the crane. Valve 74 is connected to cylinder 84, and valve 73 to cylinder 83. These are the cylinders for the two yardarms or swing arms 25, one being omitted on other figures in the drawings. Valve 77 is connected to the two-way cylinder 87, which is the bucket cylinder. Thus pressure may be supplied to either end of the cylinder for raising or lowering the bucket. A special valve 72 is adapted to automatically supply additional pressure at any time when the pressure in the valve block 80 drops due to use of several motors or cylinders at substantially the same time. The individual brake cylinders 88 are all connected in parallel to the single pressure supply line. To release the brakes which are constantly on, valve 78 is closed bymeans of a pedal or the like, thus closing a vent line 78A connected between valve 78 and relief valve RV. This causes fluid pressure to be maintained in line 81 connected to the brake cylinders 88.

Operation The basic elements of the crane are transported to the location for assembly. These elements are the two end frames, the crane beam, and the power unit. Sections of track 40 are brought on location, along with a plurality of track supports 41. For purposes of illustration, it will be assumed that the location is a bridge under construction, the framework of which has been completed. It is now necessary to pour the deck concrete. This job has long been an expensive one, in view of the fact that much manual labor is required to place the concrete in place at infinite points on the bridge deck. Trucks may not drive on the falsework and concrete forms, as the trucks will damage said forms. Sections of track are assembled with the supports 41, and a section of track is placed on either side of the bridge over the girder 46, at one end of the bridge. The end frames are then placed in position, and the crane beam 50 is formed to the correct length, according to the width of the bridge. The crane beam is then fastened to the end frames, and the Whole set on the sections of track which have been previously laid at the end of the bridge. The power unit, which is mounted on a suitable platform 82, is then fastened to the extended portion 36 of one of the wheel trucks 30. The hydraulic connections are made fast between the power unit and the lines (not shown) thelength of the bridge, sections of track 40 are picked 75'' up by'the yardarms 2 5 and lowered into position over the girder 46 at each side of the bridge. All operations of the crane are controlled by an operator positioned at a point on the platform 82 so that he may operate the valves '80. With the necessary track laid and fastened together, the cranemay then be used to transfer concrete ready-mix from trucks into a hopper or bucket 99 and transfer the concrete from the bucket to any infinite point on the bridge deck. This is done by pnopelling the crane along the tracks, and propelling the trolleys along the crane beam until the bucket 99 is in the required position over the deck. The bucket is then dumped or otherwise emptied of its contents, and returned by the crane to the truck for another load. a V I At the completion of the job, or when the use of the crane is no longer required, the sections of track are unfastened, and the sections are then picked up by the yardarms under the control of the operator, and brought away to any convenient transfer point. The crane is then propelled to the remaining last sections of track at the end of the bridge. The hydraulic connections are unfastened, and the power unit is unfasteued and removed to a truck or the like. The end braces 67 are unfastened fro-m the end frames and crane beam, and the crane beam is unfastened from the end frames and lowered onto a truck or the like, as are the end frames. The portable gantry crane is then ready for transport to another location.

A modification of the crane beam is contemplated in Figure 1, wherein is illustrated an extension 250 of crane beam '50. This extended portion 250 of the crane beam forms an integral part of the construction thereof, and is formed by making up the crane beam 50 longer than the required length determined by the width of the bridge. The mounting brackets 55 are then placed inwardly along the crane beam from the end, instead of at substantially the end as hereinabove disclosed. Thus, after assembly of the crane, the portion 250 of the crane beam 50 extends outwardly over the side of the bridge.

The trolley, herein shown as at 200, having wheels 201, and loading bar 202 supports a winch 203, instead of the cylinder 87. The winch may be any conventional hydraulic winch, or any other self-powered type. The bucket 99 has an idler block 205' supporting it, and the idler block 205 has suitable cable 204 fastened at one end to the winch 203, travelling downwardly around the idler and back up to the drum of the winch 203.

In the case wherein the bridge being constructed is particularly long, say for instance several hundred yards, much time will be consumed having the crane travel back and forth the entire length of the bridge for a load, or even from substantially the midpoint thereof to one end. Using the extension 250, the bucket may be positioned away from the side of the bridge, and then lowered to a vehicle below to receive a load. It will become obvious that the bucket is also adapted to be lowered to a barge to receive a load if the bridge is over water. The bucket is also adapted to be replaced by any apparatus adapted to receive and transport a load of any required type. Thus, any materials required for construction of the bridge are adapted to be hoisted into position from a vehicle or barge below the bridge, or from a vehicle at one end of the bridge, or from either end of the bridge.

In the modification of the crane beam, the bucket is connected to the trolley so that the bucket may be placed at infinite points on the bridge, and the trolley is connected by means of the chain .103, as hereinabove disclosed.

It will thus become obvious that there is embodied a portable gantry crane comprising a pair of end frames, a single, internal power source, and a crane beam made of sections of the beam construction. The whole is adapted to be transported on location, assembled, operated, dismantled, and transported from location. The crane may be assembled in varying lengths of the crane beam for operation according to requirements of the location of operation.

There is further embodied a single, internal power source for a crane, whereby the crane is adapted to be propelled on location by'internal power; is adapted to have its primary raising and lowering means actuated by the same internal power source; is further adapted to have its brakes actuated by the same power source; and is further adapted to have secondary raising and lowering means, such as the yardarms, actuated by the same internal. power means. A modification of the crane is adapted to transport a load from below the bridge, up over the side of the bridge at any point therealong, and thence place the load at any infinite point on the bridge.

The embodiment illustrated and described herein is for the purpose of illustration only, and not for limitation as ,to the specificv structure thereof. Modifications and other changes may be made from time to time which fall fairly within the spirit and scope of the appended claims.

I claim:

1. A portable gantry crane for movement along a path defined by spaced parallel tracks, said crane comprising a pair of inverted U-shaped frames including a spaced pair of upright members and a transverse top beam, a

crane beam extending between the top beams and sup ported thereby, and a hydraulic pressure system on said crane for operating said gantry crane; wheeled trucks supporting said end frames for movement along the track; said crane beam including a primary structural beam and a reinforcing framework forming an integral part thereof; said crane beam including a trolley reciprocably mounted thereon for movement of "a load toward or away from said end frames; said hydraulic pressure system including a power-driven pump, a hydraulic motor operatively connected to said trolley for propelling the same, hydraulic motors drivingly connected to said wheeled trucks, hydraulic motors and brakes operated by said motors against the wheels of said wheeled trucks, and valves controlling the supply of pressurized fluid to said motors.

2. The combination according to claim 1 including; a pivotallymounted yardarm on each of said end frames, said yardarm having a sheave mounted thereon, a cable mounted over said sheave, hydraulic power means operably connected to said cable, whereby said yardarm is ada ilted for raising and lowering track for said wheeled truc s.

3. The combination according to claim 1; said powerdriven pump and said valves being mounted as a unit with a reservoir of fluid, the said unit being mounted on a platform, said platform being detachably mounted on one of said end frames, said crane beam being detachably mounted to each of said end frames for support thereby, whereby said crane may be assembled and dismantled.

4. The combination according to claim 1; said crane beam being formed of sections thereof, said sections being detachably attached one to another to form said crane beam; whereby said crane beam is adapted to be formed in varying lengths.

5. The combination according to claim 1; said crane beam having an extended portion at an end thereof, said trolley being adapted to be propelled to the end of said extended portion for transporting a load past the side of said gantry crane.

References Cited in the file of this patent UNITED STATES PATENTS Germany May 9, 1941 

